基于EL模型的NPC-UPQC混合无源控制方法

摘要

在传统两电平统一电能质量调节器的基础上,采用三电平二极管箝位型逆变器代替三相桥式逆变器,构成二极管箝位型统一电能质量调节器的主电路.针对基于瞬时无功功率理论的二极管箝位型统一电能质量调节器补偿量检测方法中使用锁相环所带来的误差,提出无锁相环的基于电网工频时钟的dq0检测法,对电压和电流畸变分量分别进行实时检测.为提高二极管箝位型统一电能质量调节器的控制性能,建立并分析了二极管箝位型统一电能质量调节器的欧拉-拉格朗日模型,基于该模型与二极管箝位型统一电能质量调节器的无源性,设计了混合无源控制器.利用提出的补偿量检测方法和混合无源控制器,可有效补偿电压或电流,使负载电压或电源电流为近似正弦波.利用Matlab/Simulink软件搭建二极管箝位型统一电能质量调节器的仿真模型,对二极管箝位型统一电能质量调节器的补偿性能进行了仿真研究,并对实验结果进行了分析.仿真结果验证了本文提出的检测方法及混合无源控制策略的有效性.%A three-phase bridge inverter is replaced by a three-level neutral point clamped(NPC)inverter to construct the main circuit of NPC-unified power quality controller(UPQC)based on a traditional two-lever UPQC.To overcome the errors caused by using the detection method with phase locked loop(PLL)for NPC-UPQC compensation quantities based on instantaneous reactive power theory,a dq 0 detection method based on power grid frequency clock without PLL is proposed for the real-time detection of the distortional components of voltage and current,respectively.To improve the control performance of NPC-UPQC,a Euler-Lagrange(EL)model of NPC-UPQC is set up and analyzed,and a hy?brid passivity-based controller is designed based on the EL model and the passivity of NPC-UPQC.Using the proposed detection method for compensation quantities and the hybrid passivity-based controller,the voltage or current can be compensated effectively,which makes the waveform of load voltage or power supply current sinusoidal approximately.A simulation model of NPC-UPQC is built in Matlab/Simulink to study its compensation performance,and the experimen?tal results are analyzed.Simulation results show the effectiveness of the detection method and the hybrid passivity-based control strategy proposed in this paper.